Cryogenic refrigerator



May 11, 1965 H. M. LONG ETAL CRYOGENIC REFRIGERATOR Filed July 19. 1963 HIII;

INVENTORS M. LO N G HUGH STANLEY L. WILSON W1 ATTORNEY United States Patent 3,182,462 CRYQGENIC REFRIGERATOR Hugh M. Long and Stanley L. Wilson, Tonawanda, N.Y., assignors to Union Carbide Corporation, a corporation of New York Filed July 19, 1963, Ser. No. 296,190 8 Claims. (Cl. 6255) This invention relates to cyrogenic refrigeration apparatus and particularly to such apparatus wherein an article can be refrigerated by a body of cryogenic liquid.

A primary object of the present invention is to provide compact apparatus for refrigerating an article wherein the article and a storage body of cryogenic liquid used to refrigerate the article are contained within the apparatus in compartments which are thermally isolated from one another. Another object is to provide such apparatus with a valve-controlled supply line for supplying cryogenic liquid from the storage body to the article as required to maintain the desired temperature of the article. A further object is to provide means for independently regulating the vapor pressure of each compartment to permit long term operation of the refrigeration apparatus over the range of temperatures obtainable by such pressure adjustment without interruption when refilling the cryogenic liquid body storage compartment. These and other objects and advantages of the present invention are hereinafter described in conjunction with the accompanying drawing which shows an elevational view of refrigeration apparatus embodying principles of the present invention.

The apparatus of the present invention comprises an outer jacket, an elongated inner compartment positioned within the outer jacket, a cryogenic liquid storage vessel positioned within the outer jacket around at least a section of the inner compartment, and a valve-controlled cryogenic liquid supply line interconnecting the interiors of the storage vessel and the inner compartment to control cryogenic liquid fiow from the storage vessel to the inner compartment. The space between the outer jacket and the inner compartment is evacuable and the storage vessel is spaced from the outer jacket and the inner compartment such that the evacuable space extends therebetween so as to thermally isolate each from the other when the space is evacuated.

The valve in the cryogenic liquid supply line comprises a valve housing and element which can be located in either the storage vessel or attached to the lower section of the storage vessel in theevacuable space. In either location, the valve is preferably constructed such that it is actuated through an elongated valve stem which extends from the valve housing upwardly through the storage vessel and through a valve stem housing connected between the upper section of the storage vessel and the upper section of the outer jacket. The upper end of the valve stem is connected to a valve actuating means attached to the upper section of the valve stem housing conduit.

Both the storage vessel and the inner compartment are preferably provided with valve means communicating with the respective vapor spaces to permit independent regulation of the vapor pressures therein. Consequently, the storage vessel and the inner compartment can be maintained at separate temperatures over the temperature range obtainable by vapor pressure adjustment. This independent regulation permits refilling the storage vessel at atmospheric pressure, for example, while the inner compartment is maintained at a temperature corresponding to either over-or-under atmospheric pressures. When the article to be refrigerated within the inner compartment is one that requires long term, uninterrupted refrigeration at such a temperature, the independent pressure regulation feature of the present invention is particularly useful.

Referring to the figure, which shows the preferred embodiment of the present invention, the apparatus of the present invention comprises an outer jacket 10, an elongated inner compartment 12 positioned within the outer jacket 10 such that an evacuable insulating space 14 is provided therebetween and such that the interior of the inner compartment 12 is accessible from the exterior of the outer jacket 10 through its mouth 16. An annularshaped cryogenic liquid storage vessel 18 also is positioned within the outer jacket 10 around at least a section of the inner compartment 12 and is spaced from the inner compartment 12 and the outer jacket 10 such that the evacuable insulating space 14 extends therebetween. A cryogenic liquid supply line 20 is connected to the inner compartment 12 and to the storage vessel 18, and a valve 22 is positioned in the supply line 20 to permit cryogenic liquid flow from the storage vessel 18 to the inner compartment 12.

The mouth 16 of inner compartment 12 is attached to the upper end of the outer jacket 10 by a spud 24 and the interior thereof is sealed by a removable cap 26. The cross-sectional area of the mouth 16 is preferably large enough to facilitate the insertion or withdrawal of an article from the lower end of the inner compartment 12.

Valve 22 is preferably a modified needle-type valve wherein valve housing 28 contains a valve seat 30, and an elongated valve stem 32, having a needle-type valve element 34 at its lower end and an actuating means 36 at its upper end, extends from the valve housing 28 upwardly through the storage vessel 18 and through a valve stem housing 38. Valve stem housing 38 is gas-tightly connected between the upper ends of the storage vessel 18 and the outer jacket 10, and preferably extends downwardly through the storage vessel 18 and connects to the valve housing 28 as shown. When the valve stem housing 38 completely encloses the valve stem 32 as shown, at least one passage 40 must be provided therein so that the cryogenic liquid may reach the valve 22.

As shown in the figure, the storage vessel 18 is preferably solely supported by suspension from the outer jacket 10. Valve stem housing 38 provides one vertical support and a cryogenic liquid filling and vapor venting conduit 42 provides a second vertical support in the preferred embodiment. The multiple function valve stem housing 38 and filling conduit 42 permits use of a minimum of connections between the warm outer jacket 10 and the cold storage vessel 18 thereby minimizing the ambient heat inleak. Heat inleak may be further minimized by employing a high quality thermal insulation in the portion of the evacuable insulating space 14 between the outer jacket 10 and the storage vessel 18.

Both the storage vessel 18 and the inner compartment are provided with valve means communicating with their respective vapor spaces to permit independent regulation of the vapor pressure therein. Valve stem housing 38 is provided with such a valve means 44 in the preferred embodiment to control the vapor pressure within the storage vessel 18, and at least one passage 46 is also provided in the section thereof within the storage vessel 18 so that there is gaseous communication between the valve means 44 and the vapor space within the storage vessel 18. Spud 24 is also provided with such a valve means 48 in the preferred embodiment to control the vapor pres-sure within the inner compartment 12.

Cryogenic liquid supply line 20 is essentially the only physical connection between the inner compartment 12 and the storage vessel 18 along which heat could be transferred from one to the other. Therefore, supply line 20 is preferably elongated and coiled within the lower portion of evacuable insulating space 14 to minimize such heat transfer.

As an exconduit 42. A cryoelectronic component is placed in the bottom of the inner compartment 12 and the cap 26.

is secured. Then valve 22 is opened and a portion of the liquid helium in storage vessel 18 is transferred to the inner compartment 12.. The vapor space within the inner compartment 12 is pumped to a subatmospheric pressure through valve means 48 to lower the temperature of the a liquid helium therein as much as possible and thCOP6Ifl-. tion of .the cryoelectronic component is begun. As the liquid helium within the inner compartment gradually evaporates, more liquid helium is transferred thereto from the storage vessel 18 and, when the storage supply is depleted,'the storage vessel 18 maybe refilled through conduit 42 without affecting the operation pressure and temperaturewithin the inner compartment 12. When the life-test of the cryoelectronic'component is completed, the cap 26 is removed and the component withdrawn from the inner compartment 12.

Because the vapor space pressures of the inner compartment-12 and the storage vessel 18 can be independently controlled, the temperature within the inner compartment 12 can be varied during the component test without affecting .the temperature of liquid helium stored within the storage vessel 18. This feature of the invention permits maximum versatility of the apparatus,- without deleteriously affecting the refrigerant liquid storage capacity of the apparatus .as-might occur if thetemperature of the stored liquid within storage vessel 18 were also varied.

While the preferred embodiment of the invention has beendescribed above, it is to be understood that there are numerous other arrangements that may be devised by those skilled in the art which are within the scope of the invention.

What is claimed is:

1. Apparatus for refrigerating a component with a cryogenic liquid which comprises an outer jacket; an elongated inner compartment suspended within said outer jacket from the upper-section thereof and positioned'within said outer jacket .such that an evacuable insulating space is provided therebetween and having an opening at the upper end such that the interior of the inner compartment is accessible from the exterior of said outer jacket; removable closure-sealing means for said opening; a cryogenic liquid storage vessel positioned within said outer jacket around at least a section of said inner compartment and spaced from said inner compartment and said outer jacket such that said evacuable insulating space extends therebetween; means for suspending the storage vessel from the upper section of said outer-jacket independently of said inner compartment, a cryogenic liquid supply line connected at opposite ends to said inner compartment and the storage vessel, and a valve housing positioned at least partially in said storage-vessel in fluid communication with the supply line'and constructed to permit cryogenic liquid flow from said storage vessel to said inner compartment.

2. Apparatus according to claim 1 including a valve housing for said valve, an elongated valve stem housing extending gas-tightly from the upper section of said stor 4;. age vessel/to the upper section of said outer jacket, and a valve stem connected to said valve and extending through the valve stem housing to the exterior of said outer jacket.

3. Apparatus according to claim 1 including a cryogenic liquid filling and vapor venting conduit for said storage vessel extending gas-tightly from the 'uppersec tion of said storage vessel to the upper section of said outer jacket.

4. Apparatus according to claiml including a valve housing for said valve, an elongated valve stem housing extending gas-tightly from the upper section of said storage vessel to' the upper section of said outer jacket, and a valve stem connected to said valve and extending through the valve stem housing to the exterior of said outer jacket; and including a cryogenic liquid and vapor venting conduit for said storage vessel extending gastightly from the upper section of said storage vesselto the upper :section of said outer. jacket; said valve stem housing and said cryogenic liquid filling and vapor venting conduit being so constructed and arranged to suspend said inner vessel from said outer jacket and to provide the sole vertical support. for said storage vessel.

5. Apparatus according to claim '1 including valve means communicating with the vapor spacesof said storage vessel and said inner compartment to provide independent regulation of the vapor pressure therein.

6. Apparatus according to claim 2 wherein said valve I stem housing is so constructed and arranged to provide communication therethrough to the vapor space in said storage vessel; and including valve means in said valve stem housing for controlling the vapor pressure within said storage vessel.

7. Apparatus according .to claim 2 wherein said valve stem housing extends downwardlythrough said storage vessel to said valve housing and contains passages therethrough permitting cryogenic liquid flow from said storage vessel into said valve.

8. Apparatus according to claim 2 whereinsaid'valve stern comprises a needle-type valve element at the lower end thereof and a .valve actuating means at the upper end thereof; and wherein said valvehousing comprises a valve seat for said needle-type valve element;: said needle-type valve element being so constructed, and arranged to control the flow of cryogenic liquid from said storage vessel when actuated by said valve actuating means.

References Cited by the Examiner UNITED STATES PATENTS 2,816,232 12/57 Burstein 62-514 3,025,680 3/62 De Broose et al 62-514 FOREIGN PATENTS 123,538 11/59 Russia.

OTHER. REFERENCES Advances in Cryogenic Engineering, vol. 5, publishedby Plenum Press, Inc., New York (1960). Article by Nicol et al. on pages 332-337 relied on.

Instruments and Experimental Techniques, No. 4 (Russian), July-August 1960. Article by Fradkov on pages 126-130 relied on.

ROBERT A. OLEARY, Primary Examiner, 

1. APPARATUS FOR REFRIGERATING A COMPONENT WITH A CRYOGENIC LIQUID WHICH COMPRISES AN OUTER JACKET; AN ELONGATED INNER COMPARTMENT SUSPENDED WITHIN SAID OUTER JACKET FROM THE UPPER SECTION THEREOF AND POSITIONED WITHIN SAID OUTER JACKET SUCH THAT AN EVACUABLE INSULATING SPACE IS PROVIDED THEREBETWEEN AND HAVING AN OPENING AT THE UPPER END SUCH THAT THE EXTERIOR OF THE INNER COMPARTMENT IS ACCESSIBLE FROM THE EXTERIOR OF SAID OUTER JACKET; REMOVABLE CLOSURE-SEALING MEANS FOR SAID OPENING; A CRYOGENIC LIQUID STORAGE VESSEL POSITIONED WIHTIN SAID OTER JACKET AROUND AT LEAST A SECTION OF SAID INNER COMPARTMENT AND SPACED AT LEAST A SECTION OF SAID INNER AND SAID OUTER JACKET SUCH THAT SAID EVACUABLE INSULATING SPACE EXTENDS THEREBETWEEN; MEANS FOR SUSPENDING THE STORAGE VESSEL FROM THE UPPER SECTION OF SAID OUTER JACKET INDEPENDENTLY OF SAID INNER COMPARTMENT, A CRYOGENIC LIQUID SUPPLY LINE CONNECTED AT OPPOSITE ENDS TO SAID INNER COMPARTMENT AND THE STORAGE VESSEL, AND A VALVE HOUSING POSITIONED AT LEAST PARTIALLY IN SAID STORAGE VESSEL IN FLUID COMMUNICATION WITH THE SUPPLY LINE AND CONSTRUCTED TO PERMIT CRYOGENIC LIQUID FLOW FROM SAID STORAGE VESSEL TO SAID INNER COMPARTMENT. 